A die is known from DE 1,758,789 for producing curved is surfaces on objects made of porous, elastic materials such as foam, foam rubber, and the like. The die has or is a plunger that is provided with cutouts for the curved surfaces to be produced, and the parts of the material that are not being compressed by the die bulge out into these cutouts and are cut off, whereupon after the pressure is relieved the cut edges form the desired curved surfaces.
A device is known from DE 1,891,607 for mechanically cutting out symmetrical and asymmetrical three-dimensional bodies made of synthetic foam plates and similar materials, in which a band saw cuts the pressed foam into a shape. A cylindrical press roller that presses the workpiece into a flat shape is provided that is transported in a straight line on a work platform just below the roller die at a speed that is equal to the circumferential speed of the roller. Downstream from the roller a blade rotating transversely with respect to the transport direction of the die is provided that cuts the foam approximately in the center plane thereof, and an adjuster is provided for setting the distance between the upper edge of the die and the lower edge of the roller, and also the height of the blade.
A press die is known from DE 1,709,739 for forming bodies from porous substances such as foam rubber, sponge rubber, synthetic foam, or the like, having a concave lower surface and a flat top surface. The die, which has a box or tubular shape, for example, has a base at the bottom with an opening whose outer edge has the shape of the largest circumference of the cavity that is intended to receive the body to be shaped. A disk that is fitted into the die parallel to the base and that can be moved inward is used as a pressure ram, so that the material to be pressed is pressed between the ram and the base, and a section of the pressed material that bulges out from the cover opening can be cut off using a blade guided on the surface of the base.
A method is known from DE 3,522,192 for making a body composed of a blank made of foam, rigid foam, or the like by using a hot wire or thermal cutting device or the like. Several imaginary planes through the blank are provided. Defined points at each tangent to a plane are connected, on or outside the blank, to corresponding defined points at the corresponding tangent to the adjacent plane, on or outside the blank, by use of flexible, heat-resistant connections, and the cutting element is guided along these connections.
The cutting of contours in foam is known. It is also known to make die cuts in foams using an extrusion or die cutting machine. To this end, in one work step a section of a foam blank originally in the shape of a block, for example, is pressed into a first negative die, also referred to as a first die. The section of the foam pressed into the negative die is then cut off using an oscillating or rotating blade, for example. After further transport the foam re-expands, at which point at least one first die cut corresponding to the first negative die is made in the foam. The negative die may be made of wood or aluminum, for example.
A disadvantage of this procedure is that it is not suitable for making complex die cuts, i.e. sharply angled cutouts, for example, in the foam at great or different depths. The cut is rough at the edges and the surfaces are not smooth.